Low cost ZVS PFC driver for power LEDs

This paper presents a low cost converter for driving power light emitting diodes (LEDs). The converter is a series-resonant half-bridge with reduced DC-link capacitor which increases the conduction angle of the bridge rectifier and the power factor. It also allows the elimination of electrolytic capacitors, making the converter suitable for long life applications. Due to the resonant operation, there is no need for a current sensor to stabilize the average current through the LED string and it operates with zero-voltage-switching clamped-voltage (ZVS-CV). The simplification of the control design, and of the converter, reduces the component count and the cost. Analytical results are verified by laboratory experiment.